Weighted Average Assumptions Used in the Measurement of Net Periodic Benefit Cost (Detail)	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.31%	3.71%	4.11%
Expected long-term rate of return on plan assets	5.44%	5.28%	5.76%
Other Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.90%	3.30%	3.60%
Other Benefits | Canada
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.90%	3.40%	3.80%